DE2930021A1 - FIXING DEVICE FOR TONER IMAGES - Google Patents

Description

Fixing device for toner images

The invention relates to an apparatus for heating and fixing a toner image to a Carrier material.

In one known device, a toner image carrier material is used held under pressure between two rollers and transported by these, at least one of the rollers is heated to thereby fix the toner image. Usually there is one on a shaft At the end of one of the two rollers, a torque transmission device connected to an element such as a gear, via the transmission device the rotational force generated by a drive source such as an electric motor becomes rotationally driving the shaft and accordingly transferred to the roller with this shaft. The other roller is usually designed so that they through the frictional force is rotated between it and the driven roller. In any case, the warmth will be the Roller partially from the torque transmission device recorded. Accordingly, the temperature becomes

VI / rs

909886 / 08A4

Deulscl.e Bank (Munich) KIo 51/61070

Dresdner Bank (Munich) KIo 3939844

Postal check (Munich) KIo. 670-43-804

β 981-6293O0-2-1

at the end of this roller where the torque transmission device connected is lower than the temperature at the other end of the roller. One between the temperature difference between the opposite ends of the "roll" results in a difference in diameter between the opposite ends Ends due to a difference in thermal expansion. This makes a difference in Pressure between the two rollers and between the opposite ends of the same. If this If the difference becomes large, the toner image carrier material is wrinkled, or moves at an angle or in a serpentine manner, so that it can get caught on different elements attached along the transport path, what a Clamping or an inhibition or the like. Results. In particular if / when the toner image carrier material is a long continuous sheet or a long uninterrupted path is, as it is in a device for printing the Output signals from an electronic calculator are used

-0 is caused a large temperature difference between "the opposite ends of the roll, that the sheet or web in the station for the application - the toner image to the web (in bezug- to the transport path at a location upstream of the fixing device ^J lies) is offset laterally out of its normal transport path, so that the toner image applied to the path is also offset laterally; in the extreme case, the continuous path tears or separates.

The long continuous web is then usually severed

or torn when they are 1 mm or more out of a predetermined transport path is offset out laterally.

The invention is based on the object to provide a heating roller fixing device in which a

909886/0844

Toner image carrier material is constantly conveyed over a predetermined transport route.

Furthermore, with the fixing device according to the invention a toner image support material in the form of a long continuous web consistently or uniformly be transported via the predetermined transport route. The continuous track should be transported without tearing will. Furthermore, the continuous path should be without displacement from a predetermined transport path in the Image application step that precedes the fusing.

The invention is explained below on the basis of exemplary embodiments with reference to the drawing explained in more detail.

Fig. 1 shows a print output device

for the output signal of an electronic computer in which the fixing device is usable.

Fig. 2 is a perspective view for explaining some Embodiments of the device.

Fig. 3 is a front view of the device of Fig.

Fig. 4 is a diagram showing

showing the relationship between a temperature difference between opposite Shows ends of a roller and an offset of a toner image carrier material.

909886 / 08U

_B981f ? 930021

Fig. 5 shows an example of a control device. - "-.

Fig. 6 shows an example of a detector circuit.

Fig. 7 shows another example of a control device.

8 to 11 show further exemplary embodiments of the fixing device.

Fig. 12 is a plan view of a next embodiment of the fixing device. "

FIG. 13 is a partial front view of the device of FIG. 12.

Fig. 14 shows an example of a control device.

Fig. 15 shows an example of a detector circuit.

In FIG. 1, a laser beam emitted by a laser oscillator 1 enters a light modulation system a, which consists of a lens 2, a known acousto-optical modulating element 3, to which the output signal

of a computer is applied, and a lens 4 is formed. The by means of this system according to the created Signal-modulated beams pass through a beam expander 5 and hit a polygonal mirror 6, which is rotated by means of a motor 7.

The beams deflected by means of the rotating mirror 6

909886/0844

- 12 - B 981

'are converted into parallel beams by means of a lens 8 and hit a photosensitive drum 9.

The photosensitive drum 9 attached to her Peripheral area an electrophotographically sensitive Material composed of an electrically conductive support material, a photoconductive layer and an insulating cover layer in this order is rotated at a constant speed. During the rotation, the photosensitive drum first uniformly charged by means of a first corona discharger 11 and then by means of a second corona discharger 12 of an alternating current corona discharge or a direct current corona discharge subjected to polarity opposite to the polarity of the discharger 11, while doing so by means of the Rays is irradiated; thereafter, the drum becomes uniform over the entire surface by means of a Lamp 13 illuminated. Through the above-described

^{For the} process, an electrostatic charge image corresponding to the recording signal of the computer and having a high contrast is generated on the photosensitive material, which is then developed in a developing device 14 with heat-fusible color particles (toner). The image developed in this way is transferred in an image transfer station by means of an image transfer charger 17 onto zigzag folded paper 20, which is a long continuous J-paper web and at a speed equal to the circumferential direction.

speed of the photosensitive drum 9 is transported under pressure to the drum 9 in the direction of the arrow will. The toner image transferred in this way is fixed by a fixing device shown below is written on, heated and attached to the paper web

20 fixed. On the other hand, after the image transfer

909886 / 084Λ

the photosensitive material by means of a cleaning device 18 cleaned so that it is ready for another imaging cycle. If that sucked, Carlson method is used as the electrophotographic method, the discharger 12 and the lamp 13 can be used can be omitted.

The transport of the long continuous paper web 20 will now be described. Paper of this type is commonly used for computer output and has perforations in it at predetermined intervals Longitudinal direction, which allow the folding of the paper, as well as transport holes at its opposite one another Margins. The paper web 20 is fed out of a container 20 'for the paper supply and after the image transfer and fixing in a container 20 ″. The paper web 20 is from the container 20 ' all the way up to the container 20 ". For a smooth or shock-free transport of the paper web A holding rod 21 is provided. A brush 22 is mounted so that it the paper web 20 against a Guide plate 23 presses in order to prevent the paper web 20 from entering a pulling device 24 floats or takes off; in this way the transport of the paper is evened out. The brush 22 also serves to remove dust or the like adhering to the paper web 20. The pulling device 24 is a pulling device known type, are arranged on the pins for engagement in the transport holes of the paper web 20, the

are set in circulation by rotation of a pulling device shaft, not shown, in order to thereby the paper web 20 to be transported at constant speed in the direction of the arrow. This creates a latitude offset the paper web 20 prevents the pulling device. 25 and 29 are guide rollers for paper transport.

909886/0844

27 and 28 are image transfer guide plates which are selectively positioned between an illustrated first position for the essentially tangential pressing of the paper web 20 against the peripheral surface of the photosensitive Drum and a second position which is further away from the photosensitive material. Of course, the paper web 20 is at the image transfer- station along such a transport path that the toner image formed on the drum 9 is exclusive

'0 borrowed to a predetermined width range of the paper web is transmitted without protruding beyond the width limits of the web. When the image transfer is complete is, the guide plates 27 and 28 are placed in their second position, while the paper web 20 by means of

'^ of an element 26 pressed and released from the drum 9 will. 30 is a guide roller which is used to keep the tension on the paper web 20 constant Paper web 20 intercepts caused tension changes and corresponding to the paper tension changes

is movable between the positions 30 'and 30 "shown by the dash-dotted lines. 31 is a fixing roller, is pressed against the surface of the paper web 20 carrying the toner image. 32 is a backing or Pressure roller. At least one of these two reels

is heated. The rollers 31 and 32 are longer than that Paper web 20 is wide; they transport the paper web 20 by having it between them holding opposite ends, the toner image is heated and melted to attach it to the paper web 20 to fix. To transport the paper web 20 at a speed that is equal to the peripheral speed of the drum 9, the rollers 31 and 32 are rotated in the direction of the arrows. 33 and 34 are reels for the Output of the paper web 20 subjected to the toner image fixing process into the container 20 ″.

909886/0844

The fixing device will now be described in detail. In FIGS. 2 and 3, rollers 31 and 32 are the rollers described in connection with FIG. The fixing roller 31 shown is a hollow cylindrical roller made of aluminum, the surface of which is coated with a thin layer of tetrafluoroethylene resin to prevent the toner from sticking. The pressure roller 32 shown has an aluminum roller core 32 ₁ which is covered with a relatively thick layer 32 of heat-resistant silicone rubber, the outer surface being covered by a tube made of tetrafluoroethylene resin to prevent the build-up of toner. When the paper web 20 is held under pressure between the two rollers 31 and 32, the layer 32 ^ of the resilient material is elastically deformed. In this way, the paper web 20 is pressed against the rollers 31 and 32 over a certain width with respect to its transport direction, so that the toner absorbs sufficient heat and is forcibly fixed to the paper web.

in the cavity of the fixing roller 31 is a heat source 35 arranged like an infrared lamp, which is switched on for so long even if no fixing process takes place remains as long as the main switch of the print output device shown in Fig. 1 is closed. The heat source 35 has a length which is substantially greater than the axial length of the body of the roller 31 (the cylindrical Section against which the paper web 20 is pressed); the heat source heats the roller 31 all over Length (where in terms of the longitudinal direction of the roller

^ου the distribution of the heat supplied to the roller 31 is symmetrical on both sides and preferably uniform on both sides); so that the peripheral surface of the roller is heated to such a temperature that the toner to adhere to the paper web 20 by the heat substantially

over the entire length of the roller body, but at least

909886/0844

^{B 9816} 293üU21

• is melted in the contact area with the paper web 20. However, the roller must not be heated to such a high temperature that the paper is deformed as a result. The temperature of the peripheral surface of the roller 31 differs depending on the kind of the toner and the kind of the paper, but it is usually in the range of 70 to 250 ^° C. 36 is a temperature sensing element such as a thermistor or the like the longitudinal center of the roller 31 rests against the circumferential surface of the same. The signal from this element 36 is applied to a known control circuit which controls the input power of the heat source 35 so that the temperature of the peripheral surface of the roller 31 is normally within the aforementioned selected temperature range.

No heat source is provided inside the pressure roller 32, but the temperature of this roller 32 is raised by the fact that it _{absorbs heat directly via its contact area with} the roller 31 or indirectly via the paper web 20 when it is fed into a device by means of a device described below Is brought to the position in which it cooperates with the roller 31 to hold the paper web 20. It is also possible in

"to attach a heat source to the pressure roller 32, the corresponds to that in roller 31.

According to the illustration in FIG. 3, there are hollow shafts at the opposite ends of the fixing roller 31 31 'and 31 "attached through which the heat source 35 protrudes; these shafts 31' and 31" are with the help of adiabatic bearings or bearings with low heat transmission rotatable on side plates 37 and 37 'of the fixing device stored. The shafts 31 'and 31 "protrude partially

point outward beyond the side panels 37 and 37 '.

909886/0844

On the part of the shaft 31 'that goes over the side plate protrudes, a gear 38 is attached. On the other hand, the pressure roller 32 is with the help of axle shafts 32 ' and 32 ″ protruding from the opposite ends of the roller, rotatable on pressure levers 39 or 3) ', with the shafts in (adiabatic or poorly heat-permeable) bearings in the levers are used. The levers 39 and 39 'are supported with the aid of support axles 39 "attached to them. and 39 "'are rotatably supported on the side plates 37 and 37', respectively. Those of the roller 32 with respect to the support axes 39 "and 39" 'opposite ends of levers 39 and 39 "are provided with electromagnetic plungers, not shown tied together. During the fixing process, the plungers

'5 operated so that the ends of levers 39 and 39' press in the direction of arrows C. As a result, the roller 32 presses the paper web 20 against the roller 31.

The paper web 20 is normally under pressure

^iK} holder transported between these by means of rollers 31 and 32, the width center coinciding with the longitudinal center of rollers 31 and 32. When the desired fusing process is complete, the plungers are de-energized, thereby causing the roller 32 through her

Weight drops by a predetermined distance and disengages from roller 31. As soon as this happens the pressure holding of the paper web 20 is canceled by means of the two rollers 31 and 32.

In Fig. 2, 40 denotes a motor for the

Rotary drive of the fixing roller 31. The rotating force of the motor 40 is transmitted to roller 31 via a mechanism which will be described below. 38 is the gear, as described above on shaft 31 ' the roller 31 is attached. With the gear 38 meshes

909886/0844

Gear 43 attached to the output shaft of a magnetic powder clutch 42. On the input shaft of the Coupling 42 is attached to a control or adjusting pinion 42 '. About the pinion 42 'and also on one of the Output shaft of the motor 40 fixed adjusting pinion 40 'runs a control or adjusting belt 41. The magnetic powder clutch 42 is used as a slip clutch and results in' a constant speed rotation at a predetermined torque with high accuracy. The torque of the engine 40 is applied to elements 40 ', 41, 42', 42, 43 and 38 transferred in the order mentioned, thereby rotating the roller 31 at the same peripheral speed how to drive the drum 9. Of the various elements that make up the torque transmission mechanism described above form, the attached to the shaft of the heated roller gear 38 and that with this Gear 38 meshing gear 43, in view of its heat resistance, preferably made of a metal such as Made of steel or brass. The metal gears, however, have good thermal conductivity, so they therefore remove heat from the roller and radiate it to the outside. When the roller 32 by the function of above-mentioned plunger is pressed against the roller 31, is caused by the friction between the pressure roller

32 and the roller 31 and the paper web 20, the roller 32 at the same peripheral speed as the Roller 31 rotated.

As described above, this is a ^'lj part of the rotation force transmission mechanism forming metal-gear 38 on the shaft 31' attached to the fixing roller 31 so that it takes up the heat at the end of the roll 31, located adjacent the shaft 31 ' is. The heat absorbed in this way is given off or radiated from the surface of the gear 38 or to the tooth

909886/0844

- 19 - B 981 64. "

'Rad 43 transferred. The heat transferred to gear 43 in this way soon also flows from this gear. On the other hand, the shaft 31 "of the roller 21 is simply supported by the support side plate 37 'and is not connected to the above-mentioned rotational force transmission mechanism. Accordingly, the amount of heat given off from the end of the roller 31 adjacent to the shaft 31' is larger than the amount of heat given off from the opposite end of the roller 31. In this case, therefore, the end of the roller 31 adjacent to the shaft 31 'tends to have a lower temperature than the opposite end; corresponding end of the against the roller 31

^ 5 pressed pressure roller 32 a lower temperature at than the opposite end of the pressure roller 32. When there is a temperature difference between each other opposite ends of at least one of the rollers or in particular both the fixing roller 31 and

the pressure roller 32 occurs, however, the paper web becomes 20 moved from its predetermined transport path to the end of the roller, the temperature of which is higher is. This is due to the difference in thermal expansion of the roll diameter between the two ends.

knife traced.

Fig. 4 is a graphical representation of data obtained by measuring the temperature difference between the in the longitudinal direction left and right end of the fixing

Roller 31 and the displacement of the paper web in the direction of its width from its normal transport path are achieved (in which the width center of the paper web coincides with the longitudinal center of the roller).

909886/0844

If, according to FIG. 4, the temperature difference between the left and the right end of the roller is below 5 ^° C., the offset of the paper web is sufficiently small (namely less than 0.2 mm) that no tearing or creasing of the paper occurs and a practically sufficient printing accuracy is achieved; if, on the other hand, the temperature difference is higher than 5 ^° C., if the paper web does not tear (with a paper offset of 0.2 to 0.8 mm), the relative position between the paper web 20 and the drum 9 at the image transfer station becomes uneven, so that no sufficient printing position accuracy can be achieved. (However, if the required pressure accuracy degree is lowered, the temperature difference between the left and right ends of the roll 31 may be up to approximately 10 ⁰ C). If a temperature difference in the order of magnitude of 10 to 15 ⁰ C occurs, the paper web is greatly offset and tears, so that disturbances arise. Therefore, the permissible range of the temperature difference in this case is preferably less than 5 ^° C. and must not exceed a maximum of 10 ^{° C.} The data in Fig. 4 were prepared by use of paper having a thickness of 64 g / m ^2, a fixing roller (was heated surface thereof to 190 to 200 ⁰ C) 31 having a diameter of 80 mm and a nip roller 32 achieved with a diameter of 7 3 mm and a silicone rubber layer of 4 mm, the two rollers 3Γ and 32 were pressed against each other with a compressive force of 180 kg and the paper web 20 was transported at a speed of 230 mm / s ^. The permissible temperature differences between the opposite ends of the roller are of course dependent on the selected tolerance range for the paper offset, the material, the temperature, the speed and the diameter of the roller.

The pair and the thickness of the paper can be changed. In which

909886/0844

• The embodiment example has the pressure roller 32 a Metailkern, which is covered with a relatively thick silicone rubber layer, to a to provide sufficient width of pressure contact between rollers 31 and 32; which has silicone rubber a larger coefficient of thermal expansion than the metal such as aluminum of the fixing roller 31. Therefore, the diameter of the pressure roller 32 from one end to the other end is also small Temperature difference different, so that consequently when a material with a relatively large Thermal expansion coefficients like silicone rubber is used for the two rollers 31 and 32 or for one of these rollers, the temperature difference between

'^ the opposite ends of the rollers must be reduced to a minimum. This also applies to the case where the two rollers 31 and 32 each have a Metalikern, ^υ is only covered with a thin layer of a material for preventing the piecing, such as with a layer of tetrafluoroethylene resin.

To prevent the paper web 20 from tearing as well

the width offset of the paper web 20 from its

predetermined transport path that maintains the transfer of the desired toner image at the image transfer station on the paper web 20 in a predetermined width position of the toner image are allowed at the following devices applied to the embodiment according to FIGS. 2 and 3:

With a blower 47 is designated. This blowing fan 47 results in a cooling air flow toward that portion of the time 31 "of the fixing roller 31, which protrudes outwardly from the side plate 37 ', the shaft 31' is attached to the end, the orphan end of the

909886/0844

opposite, which due to its connection to the torque transmission mechanism with the gear 38 strives to assume a relatively low temperature. The blower starts to initiate of the heating of the heat source 35 to blow and ends upon the termination of the heating of the heat source. Through the Air flow from the blower fan 47 accelerates the heat dissipation of the shaft 31 ″, which lowers the temperature at the end of the fuser roller adjacent to the shaft 31 ″ 31 results. The flow rate applied by the fan 47 per unit of time is selected so that the per unit of time the amount of heat removed from the shaft 31 ″ by the air flow is essentially equal to the amount of heat, per unit of time by the torque transmission mechanism is carried away with the gear 38 from the shaft 31 '. In this way the temperature distribution will increase the fixing roller 31 is essentially symmetrical on both sides with respect to its longitudinal direction, so that the temperature difference between the opposite

Ends of the roller 31 is zero or takes a small value within the permissible range. Accordingly the temperature distribution on the pressure roller 32 with respect to the longitudinal direction of the same is inevitable also essentially symmetrical on both sides, see above

^ZJ that the temperature difference between the opposite ends of this roller also becomes zero or assumes a small value within the permissible range. That is, the differences in thermal expansion between the opposite ends of the rolls

31 and 32 become essentially zero. As a result, the paper web moves smoothly on the predetermined one Transport route without being torn, pinched or wrinkled; so that at the image transmission station

achieved a high level of printing accuracy. 35

909886/0844

The fan 47 can during a predetermined Time interval are operated. In such a case, the fan 47 is put into operation before the temperature at the end of the fusing roller adjacent to the shaft 31 ' 31 lower than the temperature on the opposite End is at which the temperature difference between the opposite ends of the fusing roller 31 (and accordingly the pressure roller 32) exceeds the permissible range; the fan goes out of operation set before the temperature at the end of the roller 31 adjacent to the shaft 31 ″ is lower than the temperature at the opposite end where the temperature difference exceeds the allowable range. The time interval is set by means of a timer.

In the next embodiment, the Temperature difference between the opposite ends of the roller is detected in order to correspond to the Acquisition to correct the temperature difference.

In FIGS. 2 and 3, 44 and 45 are temperature sensors such as thermistors or the like. These temperature sensors 44 and 45 lie against the peripheral surface of the body of the fixing roller 31 at its ends, which correspond to the shafts 31 'and 31 "are adjacent.

Fig. 5 shows detector circuits 5-1 and 5-2, the resistance value changes of the temperature sensors

4 4 and 45 convert into voltage changes and these on

Detect changes, and a conventional comparator 5-3, the output voltages of the detector circuits 5-1 and 5-2 compares with each other and outputs a signal with TTL level. The comparator 5-3 gives a signal high level when the output voltage of the detector

circuit 5-1 higher than the output voltage of the detector

909886/0844

- 24 - B 9816

circuit 5-2, and a low level signal when the output voltage of the detector circuit 5-1 is lower than the output voltage of the detector circuit 5-2. 5-6 is a driver circuit for driving the Fan 47 designated. Circuit 5-6 drives the fan when a high level signal is applied to it while it does not operate the fan when a low level signal is applied.

When the temperature of the peripheral surface of the roller 31 at the end adjacent to the temperature sensor 4 4 lower than the temperature of the peripheral surface of the roller 31 at the end adjacent to the temperature sensor 4 5 becomes the resistance value of the temperature sensor 44 higher than that of the temperature sensor 45. Accordingly, the output voltage of the detector circuit becomes 5-1 higher than the output voltage of the detector circuit 5-2, so that the output of the comparator is high Level assumes. As a result, the input to the fan drive circuit 5-6 is high. This will the fan 47 is driven so that the end portion of the roller 31 adjacent to the temperature sensor 45 is cooled will. At the time when, due to the function of the fan 47, the temperature at the temperature sensor 45 adjacent end portion of the roller 31 is slightly lower than the temperature at the temperature sensor 4 4 adjacent end region of the roller 31 is, according to FIG the above description of the fan 47 is taken out of service. Due to the heat from the heat source 35 begins the temperature of the end section of the roller 31 adjacent to the shaft 31 ″ is now to rise again.

In the manner described, the temperatures

at the opposite ends of the fixing

Roller and the pressure roller controlled so that they always

909886/0844

- 25 - B 9816

are the same. Therefore, there is no difference in diameter between the two ends of the two rollers 31 and 32; if such a difference occurs, it is within an allowable range; moved that way the paper web on the previously determined transport route.

An embodiment of the detector circuit 5-1 is shown in Fig. 6; where R, .., R, -, / ^R fi3 ' ^R fi4' ^R 65 and R _{fi (} - resistors, where the resistance _{values of} the resistors R,. and R fiC - are chosen so that they are sufficiently larger than those of the resistor R ^ -, and the temperature sensor 44. OP61 is a conventional arithmetic amplifier; 44 is the temperature sensor; V61 is a predetermined voltage. Since the resistors R _fiz , and R _{fi [} - have resistance values sufficiently larger than those of the resistor R _fi3 and the temperature sensor 44 are, if V is the potential at the negative terminal of the computing amplifier OP61 and ν is the potential at the positive terminal of the computing amplifier, the following relationships apply:

V = V61 χ R _co / (R _c , + R, ^) = constant ... (6-1)

faj DJ bZ

V = V61 χ 44 / (44 + R ₁ ) ... (6-2!

The following applies to the output voltage V _{Q of} the operational amplifier OP61:

V _n = A χ (V ⁺ - V ~) ... (6-3)

Assuming that the temperature of the area in which the temperature sensor 44 is located has risen, so is the Resistance value of this temperature sensor 44 is reduced, so that according to equation (6-2), the voltage V at your

Positive connection of the processing amplifier OP61 drops. To the-

909886/0844

] accordingly, the output voltage V _{Q of} the arithmetic logic amplifier OP61 drops according to equation (6-3). In contrast, when the temperature of the region in which the temperature sensor 44 is located falls, the resistance value of the temperature sensor 44 increases analogously, so that the output voltage V _{Q of} the computing amplifier OP61 increases.

In this way, the temperature change of the temperature sensor 44 becomes a change in the output voltage V ^ implemented. The detector circuit 5-2 can also have the structure shown in FIG.

In the embodiment described, only a single blower fan is used for cooling. Additionally in addition to the fan 47, however, a fan 46 for cooling the end region adjacent to the shaft 31 ′ can be used Roller 31 can be provided. When using the fan in this way the opposite ends the roller are cooled, the temperature difference between the two ends can be suppressed quickly. " 7 shows a control or regulating device for the fans 46 and 47 Circuit parts described corresponding circuit parts have the same reference numbers. In Fig. 7, 5-4 is a conventional inverter, while 5-5 is a driver circuit for driving the fan 46. When a high level signal is applied to the driver circuit 5-5 when a low level signal is applied to the driver circuit, it drives the fan 46 5-5 the fan 46 is not operated. As can be seen from the preceding description, the Fan 47 is put into operation when the temperature at the end region of the roller adjacent to shaft 31 ″ is higher than the temperature at the end adjacent shaft 31 '

3 ^} the roller becomes. If by operating the fan 47

909866/0844

the temperature at the end of the roller adjacent to the shaft 31 "becomes lower than the temperature at the end of the roller adjacent to the shaft 31 ', the fan 46 is put into operation.
5

In the embodiment described above, the blowers generated by fans 46 and 47, respectively Air flows against the roller shafts 31 'or

31 ", but not against the bodies of the rollers 31 and 32, the shafts 32 'and 32" and the levers 39 and 39', since these elements are shielded by the side plates 37 and 37 '. But if, for example, the wave 31 "is cooled, the end of the body" adjacent to the shaft 31 "of the shaft 31 is also cooled (namely the cylinder body against which the paper web 20 is pressed), so that consequently also that of the shaft 32 "adjacent The end of the roller 32 is cooled.

8 shows a further exemplary embodiment of the fixing device. 51 is a radiator plate or Cooling plate, which is fastened to the shaft 31 ″ of the fixing roller and carries cooling fins 51 '. This cooling plate 51 absorbs heat from the shaft 31 ″ and releases this heat

"from, whereby the amount of heat given off per unit of time in is substantially equal to the amount of heat generated per unit time from the torque transmission mechanism with the gear 38, which absorbs the heat from the shaft 31 '. Consequently, those of the opposite

lying ends of the fixing roller 31 flowing heat quantities substantially equal to each other, hence the temperature difference between these ends and hence the temperature difference between the opposite ends of the pressure roller 32 becomes zero or

a small value within the allowable range.

909886/0844

takes. In short, the size difference in thermal expansion between the opposite ends of the fixing roller and the pressure roller becomes substantially zero.
5

In the embodiment described above, the end of the roller 31 adjacent to the shaft 31 "is cooled; however, it is also possible to apply more heat to the end of the roller" adjacent to the shaft 31 " than to the end of the malts adjacent to the shaft 31".

In Fig. 9, 48 denotes an auxiliary heat source which is arranged in the end of the cavity of the roller 11 adjacent to the shaft 31 * so that it heats this end of the body of the folds XI (ie in detail eo that the dem the shaft 31 'adjacent the end of the roller 31 than the quantity of heat supplied to the shaft "is the adjacent end of the roller 31). (Hereinafter has" greater than 31 heating one end of the roller "has the meaning

that the said one end of the roll amount of heat supplied is greater than that to the other end of the roll amount of heat supplied). The auxiliary heat source 48 begins to heat upon the beginning of the heating by the main heat source 35 , while the heating upon completion

the heating by means of the main heat source 35 is ended . The amount of heat given off by the heat source 4Θ per unit of time is chosen so that the amount of heat supplied per unit of time by this heat source 48 to the end of 4-waLre 31 adjacent to the wave 31 * is essentially equal to the amount of heat per unit of time from the wave 31 * through the The torque transmission mechanism is transferred to the gear wheel 31 . As a result, the temperature distribution in the Flicler-Walee becomes essentially symmetrical on both sides with respect to the longitudinal direction of the same, and the temperature distribution between the opposite ends of the roller 31 and Hull

909866/0144

or to a small value within the allowable range. This also applies to the pressure roller 32. That is, the size difference in thermal expansion between the opposite ends of the rollers 31 and 3 2 becomes essentially zero. As a result, the paper web 20 moves smoothly on the predetermined one Transport route without being torn, jammed and / or wrinkled; doing this at the image transmission station a high printing accuracy is achieved. 10

In this embodiment, the auxiliary heat source is 48 designed so that it warms as long as the main heat source 35 warms; on the other hand, the Auxiliary heat source can also be controlled so that it is used for

'5 warms a predetermined time interval. In this case is the auxiliary heat source 48 by means of a timer controlled so that it begins to warm before the end of the fuser roller 31 adjacent to the while 31 'is cooler than the opposite end of the fixing waize

^ ^υ and the temperature difference between the opposite ends of the fixing roller 31 (and consequently the pressure roller 32) exceeds the permissible range; the heating by means of the auxiliary heat source is terminated before by the action of the heat source

4 8 the temperature at that adjacent to the shaft 31 ' The end of the roller is higher than the temperature at the opposite end of the roller and the temperature difference exceeds the allowable range.

In the case of the fixation device, in which that of the while

31 "adjacent roller end is cooled in the manner described above, the temperature distribution in relation to the longitudinal direction of the roller assumes a ivije! -Like form, in which the middle area is higher than dis

are mutually opposed to each other; es: cer f x. ^s ::. irv: ": -

- 30 - B 9816

293002T

'Direction at the end of the shaft 31' supplied If the roller is supplied with more heat than the end of the roller adjacent to the shaft 31 ″, the temperature distribution will, however, be reduced flat. An apparatus in which the temperature distribution is further flattened is now referred to to FIG. 10.

In Fig. 10, 48 and 49 are auxiliary heat sources, the are arranged in the opposite ends of the cavity of the 'U fuser roller 31, so that the shafts 31 'and 31 "adjacent ends of the body of the fixing roller 31. The auxiliary heat sources 48 and 49 cooperate with the main heat source 35 so that the temperature distribution with respect to the longitudinal direction of the Fusing roller 31 becomes substantially uniform from one end to the other.

The per unit of time from the Hi Ifs heat source 49

The amount of heat given off is less than that per unit of time

the amount of heat given off by the auxiliary heat source 48. Of the The difference in the amount of heat given off per unit of time between the auxiliary heat sources 48 and 49 is essentially equal to the amount of heat generated per unit time by the torque transmission mechanism with the gear 38 of

the shaft 31 'is discharged. In this embodiment the operation of the auxiliary heat sources begins and ends 4 8 and 49 synchronous with the main heat source 35, so that the auxiliary heat sources together with the main heat source 35 heat as long as it is heating.

In the embodiment according to FIG. 10, it is also possible to close the auxiliary heat sources 48 and 49 in this way control that the heat source 48 warms synchronously with the heating by means of the main heat source 35, while the auxiliary ■ irmeqiie 1 i ο 4 9 in a predetermined time interval heat

e C "9 8 8 E · 'G 8 4 4

«Gives. In this case, the length of time during which the heat source 49 does not emit heat and the length of time during which the heat source 49 heats become corresponding to the difference between the amount of heat which is transmitted from the end of the roller 31 adjacent to the shaft 31 ″ via the shaft 31 "and the amount of heat selected which exits from the end of the roller 31 adjacent to the shaft 31 'via the shaft 31' (and accordingly via the gear 18, etc.)? As can be seen from the description so far, the temperature difference between the opposite ends of the roller 31 becomes WuIi or a small value within the permissible range. In the case of the last one based on fig. \ O explained exemplary embodiment, there is no forced fan

'5 Cooling the Walfcenendes, "at which the temperature is proportionate gets high; rather, this end of the roll is naturally cooled by stopping the heating by means of the auxiliary heat source 49.

* 0 Fig. 11 shows a further embodiment of the flKing device. In this embodiment, the distribution is that of the main heat source 35 given amount of heat on the shaft 31 'adjacent Side of the roller 11 larger than that in the longitudinal direction of the

* 'Roller opposite side. Oils main heat source 15 has a heat-resistant glass tube 35, insulating elements 15 attached to the opposite ends of the same, and a chrome-nickel wire 35 ₁ extending between the insulating elements 35. The chrome

* ^Υ nickel wire 35j to write in case of power supply of heat, has spiral portions 35 '', which more heat per unit length dl abgebtn HLB "rectilinear portions, wherein the winding sections are arranged in intervals. In this exemplary embodiment, the lengths of the winding sections 15 'are equal to one another, but the

909886/0844

β 9816293002T

between the distances to the side of the shaft 31 ' smaller and larger towards the shaft 31 ″ side. Therefore, the side of the roller 31 lying on the shaft 31 'becomes more heat is supplied than the side lying on the shaft 31 ″, which reduces the temperature difference between the opposite ends of the roller 31 are kept within the allowable range.

Also in the case of the fixing device, in which more heat is supplied to the end of the roller adjacent to the shaft 31 'than to the end of the roller adjacent to the shaft 31 ", it is possible to determine the temperature difference between the opposite ends of the roller 31 and determine it accordingly In this case, for example, as shown in FIGS. 2, 3 and 10, temperature sensors 44 and 45 can rest against the circumferential surface of the end of the roller 31 adjacent to the shaft 31 and the circumferential surface of the end of the roller adjacent to the shaft 31 ″ .
20th

When the auxiliary heat source 49 is not provided and rather only the auxiliary heat source 48 is provided, a control or regulating device can thereby be constructed that the fan 47 is replaced by the heat source 48 in the circuit according to FIG. If the temperature detected by means of temperature sensor 4 4 is lower than the temperature detected by means of temperature sensor 45 is, the output of the comparator 5-3 goes high, so that the driver circuit 5-6 causes

^ou 48 heats the heat source of the shaft 31 'adjacent the end of the roll 31st If, due to the action of the heat source 48, the temperature at the end of the roller 31 adjacent to the shaft 31 'becomes slightly higher than the temperature at the end of the roller adjacent to the shaft 31 ",

the output of the comparator 5-3 goes low, so that the driver circuit 5-6 terminates

909886/0844

_98ie £ 930 021

■ the heat dissipation caused by the heat source 48. Thereafter the heat flows at the end of the roller 31 adjacent to the shaft 31 ′ via the shaft 31 ′ and the gearwheel 38 away. This way, the temperature difference will be between the opposite ends of the roller 31 and the temperature difference at the opposite ends Ends of the roller 32 held at zero or within the allowable range, so that, accordingly, the Difference in thermal expansion between the ends of the roller 31 and the difference in thermal expansion between the ends of roller 32 both become substantially zero.

If in addition to the auxiliary heat source 48 the '5 auxiliary heat source 49 is provided, a Steuerbzw. Control circuit can be used in which, compared to the circuit of FIG. 7, the fans 46 and 47 by the Heat sources 49 and 48 are replaced. Then when the signal from the comparator 5-3 is high, the heat source is warming 48 the end of the fixing roller 31 adjacent to the shaft 31 ′ on, while at the low level of the signal from the comparator 5-3 the heat source 49 that of the shaft 31 ″ adjacent The end of the fusing roller 31 warms. In this way, the temperature difference between the opposite

lying ends of the rollers 31 and 32 held within the permissible range, so that the paper web 20 is on moved the predetermined transport path.

In the embodiment described above

are the auxiliary heat sources 48 and 49 under normal conditions out of order, namely when the temperature difference between the opposite Ends of the roller 31 is within the allowable range; however, the opposite is also possible. That is, the Temperature distribution in the fixing roller 31 with respect to the longitudinal direction thereof often takes the shape of a hill,

909886/0844

which is bilaterally symmetrical when the long or main heat source 35 is used alone, with her Middle part often shows higher temperatures than the opposite end areas. About the temperature distribution to make the roller 31 substantially uniform over its entire length, it is therefore possible to to control the auxiliary heat sources 48 and 49 so that they normally operate as long as the temperature difference between the opposite ends of the roller are within the allowable range, while when any exceeding the allowable range Temperature difference occurs between the opposite ends of the roller, which is at the Auxiliary heat source attached to the roller end with the higher temperature is put out of operation so that this end of the roller cools naturally.

In the various fixing devices mentioned, in which the position of the continuous paper web 20 in the partial area where it is held in the direction perpendicular to the paper transport direction under pressure by means of the rollers 31 and 32, is detected indirectly by the fact that the temperature difference between the opposite ends of the roller 31 is detected and is corrected according to the detection result, the temperature difference between the left and the right end of the roller 31 can always be kept below 5 ⁰ C, thereby a very uniform paper transport, a very uniform printing accuracy and a very good

To bring about fixation of the toner image.

On the other hand, if the transport speed of the paper web 20 is increased, it is known necessary the thickness of the silicone rubber layer on the

Pressure roller 32 and thus the contact width between

909886/0844

- 35 - B 981

£ 930

the fixing roller 31 and the pressure roller 32 to increase, to ensure that the toner is fused. As can be seen from the foregoing description in the case of a thick silicone rubber layer on the pressure roller 32, the amount of thermal expansion that occurs the pressure roller 32 large, so that the result of the temperature difference between the left and the right End area of the fixing roller 31 resulting in a difference in diameter between the left and right end areas the pressure roller 32 becomes larger. Therefore it is necessary to limit the allowable temperature difference between the left and right end portions of the fixing roller 31 to decrease.

According to test results, for example, with a 12 mm thick silicone rubber layer of the pressure roller 32, the allowable limit of the temperature difference between the left and right end portions of the fixing roller 31 for paper displacement in the width direction out of the predetermined transport path was less than 0.2 mm about 2 ⁰ C. It is difficult to hold in accordance with the description of the foregoing Ausführunasbeispiele solely by use of the temperature sensors 44 and 45, the temperature difference between the left and the right end portion of the fixing roller 31 to 2 ⁰ C, since here the influence of Paper dust or toner is produced and adhered to the temperature sensors. In such a case, the width offset of the paper or the paper web during its transport can be detected directly according to the embodiment according to FIGS

the fixing roller 31 to control.
35

909886/0844

Fig. 12 is a top plan view of an embodiment of the fixing device, generally in construction that shown in Figs. 2 and 3 is similar, while in this embodiment, the temperature sensor 44 and 45 are omitted. Instead is

upstream of the fixing and the pressure roller with respect to the paper transport direction, a detector 50 for Detection of the edge position of the paper web 20 is arranged. The detector 50 can alternatively also with regard to the paper-'0 be arranged transport direction downstream of the pressure contact portion. Another possibility is to to arrange the detector 50 at a location near the image transmission station shown in FIG. Furthermore, a detector 50 can be arranged either on the right or on the left edge or on both edges in the width direction of the paper.

According to the illustration in FIG. 13, the detector 50 has a light source 50 such as a light-emitting diode, an imaging lens 50 and a photoelectric converter element

ment 50 - like a solar cell. The optical axis the lens 50- is perpendicular to the paper web 20 and runs through a width edge 20 'of the paper web, if the width center axis of the paper web 20 with the center between the opposite ends of the

The fuser roller and the pressure roller match. The light source 50- sits on the optical axis of the lens 50- so that the edge 20 'of the paper web runs through the location of the image of the light source 50 ₁ formed by the lens 50-. The transducer element 50-, takes

^{l 3}

through the lens 50- the light from the light source 50 ^ on. From the foregoing it can be seen that the amount of light entering the transducer element 50- is the Position of the edge 20 'of the paper web 20 corresponds, namely the extent of the offset of the paper web 20 in their Width direction (the left to right direction in Fig. 13). If during the transport of the paper web

909886/0844

- 37 - B 981

£ 930 021

'the output of the photoelectric conversion element 50 _{3 is} higher than a prescribed level, it indicates that the paper web 20 is displaced to the left of the predetermined conveyance path in FIG. 13 (namely, toward the shaft 31' side). Conversely, when the output of transducer element 50 is lower than the prescribed level, this indicates that paper web 20 is offset to the right (namely, toward shaft 31 "). From those in connection with FIGS For reasons described in FIG. 3, when the paper web is shifted to the right from the predetermined transport path, the right fan 47 is in operation, and when the paper web is shifted to the left, the left fan 46 is in operation

set to correct the offset. 15th

Fig. 14 shows a circuit in which the output of the photoelectric conversion element 50 is used to control the fans 46 and 47. The circuit according to FIG. 14 has a detector circuit ^for 7-1 for converting the change in current of the converter element 50- into a voltage change, as well as a constant voltage source 7-2, the voltage value of which is equal to the voltage value of the detector circuit 7-1 when the paper edge 20 'with the optical axis of the lens 5O ₉ together-

falls. The circuit of FIG. 14 also has a conventional comparator 7-3, which the output voltage the detector circuit 7-1 compares with the voltage value of the constant voltage source 7-2 and that Comparison result in the form of a signal with TTL level

gives away. The comparator 7-3 outputs a high level signal when the voltage of the detector circuit 7-1 is higher than is the voltage of the constant voltage source 7-2, and a low level signal when the voltage is the Detector circuit 7-1 is lower than the voltage of the constant voltage source 7-2. The circuit according to Fig.

909886/0844

_98l £ 930 021

14 also has a conventional inverter 7-4 as well Driver circuits 7-5 and 7-6 for controlling the fans 46 and 47 by applying an input signal with TTL level. When the high level signal is applied to the driver circuits as the input signal If the input signal is low, they will drive the fans, while the fans will not operate when the input signal is low will.

If, according to FIG. 13, the paper web meanders to the right, the amount of light incident on the photoelectric conversion element 50_ is reduced, so that therefore the _{current generated by the conversion element 50 3} is reduced. Accordingly, the output voltage of the detection circuit 7-1 becomes lower than the output voltage of the constant voltage source 7-2, so that the output signal of the comparator 7-3 becomes low. As a result, a low level signal is applied to the fan drive circuit 7-5 and a high level signal is applied to the fan drive circuit 7-6, so that the fan 47 is driven to thereby drive the end portion of the fixing roller adjacent to the shaft 31 " to cool, which of course also decreases the temperature at the corresponding end of the pressure roller, in this way the offset of the paper web is corrected from its predetermined path. Conversely, if the paper web is offset to the left, the fan 46 is used for cooling of the end region adjacent to the shaft 31 '

^ O the fuser roller is driven, which of course the temperature at the corresponding end of the pressure roller falls off; this in turn corrects the offset of the paper from the predetermined transport path.

909886/0844

'In the manner described, the control takes place so that the paper web is always on its predetermined Transport moves.

A specific example of the detector circuit is shown in FIG. Rg ₁ ^ Rg ₂ ^and Rg 2 unc ^ ^ 03 are resistors, the resistance value of the resistor R ₀ "q being equal to that of the resistor Rg ₃ . OP81 denotes a conventional computer amplifier. T81 denotes a conventional npn transistor, while V81 and V82 are positive constant voltages. V83 denotes a negative constant voltage. L81 represents the incident on the detector or the transducer element 50

Amount of light.
15th

If I ₁ . is the current flowing through the transducer element 50-, it can be expressed in general as follows:

I = Ax L81 ... (8-1)

Ij

The current I- also flows through the resistor Pg ₁ ; this results in an output voltage V _n ¹ des

Computing amplifier 0P81 to:
25th

V ⁼ - ^R 81 ^{x 1} L · '· ⁽⁸ ~ ²⁾

Since Rg ₂ = R ₈₃ , the transistor T81 acts as a simple inverter, so that the output voltage V _{n of} the transistor

T81 assumes the following value:

V - ^R 81 ^{X 1} L ^{= AX R} 81 ^XL 81 ··· ⁽⁸ " ³⁾

Hence, the output voltage is V _n "of the transistor

T81 proportional to the incident light quantity L81 at the converter

909886/0844

element 50-.

£ 930 021

According to the above explanations, the end of the roller 31 adjacent to the shaft 31 ′ maintains a cooler condition than the end of roller 31 adjacent to shaft 31 ". Therefore, in most cases, the paper web 20 offset from the predetermined transport path to the shaft 31 ″. Therefore, in the circuit 14, elements 7-5 and 46 are omitted.

Further, when the fans 47 and 46 in FIG. 14 are replaced by those described in connection with FIG Auxiliary heat sources 48 and 49 are replaced, these can can be controlled by means of the detector 50. When the on the photoelectric conversion element 50 ,. falling The amount of light falls below the set amount that corresponds to the voltage of the constant voltage source 7-2, d. i.e. if the paper web is offset to the right,

^ O the heat source 48 is put into operation so as to to heat the (left) end region of the fixing roller 31 adjacent to the shaft 31, and at the same time also the Temperature at the left end of the pressure roller rises, so that the above-mentioned displacement of the paper web

· "Is corrected. If, on the other hand, the paper web after is offset to the left in Fig. 13, the heat source 49 is put into operation so that that of the shaft 31 "adjacent (Right) end of the fixing roller 31 is heated and at the same time the temperature of the right

The end region of the pressure roller rises, so that the above-mentioned offset is corrected here as well.

As described in connection with

Fig. 10 can also in the embodiment with the

Paper edge position detector 50 and the auxiliary heat sources

909886/0844

β 9βιβ? 930Ό21

48 and 49 these heat sources to compensate for the temperature distribution in the fusing roller in the longitudinal direction of the same remain in operation as long as "no displacement of the paper web from its predetermined transport path occurs out; only when the output signal of the transducer element 50 is greater or less than the set value is, one of the heat sources 38 and 49 is switched off, thereby in a natural way the To cool down roller 31 and, accordingly, a temperature drop at the corresponding end of the pressure roller bring about, whereby the offset of the paper web is corrected.

For the reason described above, elements 7-5 and 48 in the circuit of FIG. 14 can be omitted will. Furthermore, the paper edge position detector can be a non-contact detector composed of an ultrasonic wave oscillator and a receiver or a contact detector with a microswitch or the like., Furthermore the length of the paper transport holes can also be detected.

The embodiments described above are designed so that primarily not the temperature difference between the opposite ends of the pressure roller 32, but the temperature difference between the opposite ends of the fixing roller 31 is controlled, with the result that the Temperature difference between the opposite

^ου the ends of the pressure roller 32 is kept within the permissible range. This is due to the following reasons, namely that the fixing roller 31 is mounted for rotation in a predetermined position, which makes it easier to arrange the fans,

the auxiliary heat sources and the like. Leads that during the

909886/08

'' Interruption of the fixing process, namely during the Stopping the paper transport, the pressure roller 32 is at a distance from the fixing roller 31 and during this time there is no temperature difference between the opposite ends of the pressure roller arises, while, on the contrary, there is a tendency to increase in the temperature difference between the opposing ones Ends of the fixing roller 31, in which the heat source is contained (which warms as long as the

^ O main switch of the print output device is closed) and to that of the rotary driving force driving mechanism is connected, and that when between the opposite ends of the fixing roller 31 a temperature difference arises and to resume

'· * Of the fusing process, the pressure roller 32 against the roller is pressed, suddenly and inappropriately a temperature difference between the opposite ends the pressure roller 32 occurs. Essentially for the reasons mentioned above, the temperature '

^ "feelers 44 and 45 applied to the roller 31.

Devices corresponding to the devices described above for heating or cooling the roller ends can of course also for the pressure roller or else

^{J must} be provided for both the fusing roller and the pressure roller. The first solution is useful when the heat source is not located inside the fixing roller, but inside the pressure roller; the latter solution is appropriate when both

the fusing roller as well as the pressure roller contain heat sources. For the sake of simplicity, only the fixing roller 31 is shown in FIGS. 8, 9, 10 and 11; however, it goes without saying that this fixing roller is connected to the pressure roller 32 as shown in FIGS.

909886/0844

- 43 - B 981

| 93002T

The fixing device is particularly useful for fixing toner images on a long continuous path expedient in accordance with the above; however, it can also be effective for fixing Toner images can be used on cut sheets. The fixation device is not just for fixing useful in a print output device of an electronic computer, but also for fixing in an ordinary one Device for the generation of toner images.

The teaching of the invention can also be applied to a fixing device in which the heat source is not mounted inside the fusing roller, but inside the pressure roller. Furthermore, the Heat source not inside the roller, but can also be attached outside the roller; also one Auxiliary heat source can be placed outside the roller be.

With 'the invention a fixing device is created, in which a toner image carrier material is held under pressure between and by a pair of rollers is transported, wherein at least one of the rollers is heated to a temperature at which the toner image can be fixed on the carrier material; a feature of the fixing device is that the end at least one of the rollers is cooled, which tends to increase in temperature, or the opposite one Heat is supplied to the end of this one roller, whereby the thermal expansion of this one roller as well as the thermal expansion the other roller are kept in such a state that no lateral displacement of the Toner image carrier material from a predetermined

Transport path out takes place.
35

909886/0844

Blank page

Claims (19)

/ Ί, .- item no. img jue ii ^ nrien u Toriei image on a carrier 3rariai / a first and a second i-; ^r a; .r: e {3 '' or .. 2i f - ixe between each other under pressure the gate.srbx., ~ ^:. iri ^ guess :. (20) hold and transport it, - a heating device which. At least one of the rollers to a temperature at which the toner image is fixed to the carrier material and a control device (FIG. 5; FIG. 7) -, Fig. Ii), the temperature difference between the opposite ends of at least one of the salts so excited that the thermal expansion difference in size between the opposite ends of the first roller and the thermal expansion size difference between the opposite ends of the second roller substantially Be brought to zero in order to prevent a displacement of the toner image carrier material in the width direction out of a predetermined transport path. 2. Device for heating and fixing a toner image on a carrier material, characterized by a first and a second roller (31 or 32), which between each other the toner image carrier material (20) keep it under pressure and transport it, a 9 09886/0844 β _9ai6 2S30021 Heating device (35 J, which heats at least one of the rollers to a temperature at which the toner image can be fixed to the carrier material, a rotational force transmission OTi 'chtiing (38, 41 to 43) attached to a shaft (31') . • Is connected in a first end of the first roller and which transmits a rotational force generated by a drive source (40} to the first roller to drive it in rotation , and a cooling device (47; 51) which the second end of the first roller opposite the first Sridc cools, ; .; and removing from the second end of the first roller the heat in an amount corresponding to the amount of heat removed from the rotating force transfer device from the first end of the first roller , thereby reducing the thermal expansion of the first and second rollers in such a state ! : ': ■ to keep that a displacement of the toner image carrier material in the width direction out of a predetermined transport path is prevented, 3. Device according to claim 2, marked by "20 characterized in that the cooling device (47; 51) during the Operation of the heating device (35) continuously in operation is. 4. Apparatus according to claim 2, characterized in that the cooling device (47) during the Operation of the heating device (35) is operated intermittently. 5. Apparatus according to claim 2, characterized in that the cooling device has a heat sink (51) which is connected to the shaft (31 ") at the second end of the first roller (31). 6. Device for heating and fixing a toner image on a carrier material, characterized by a 909886/0844 first and a second roller (Z ^! 'i bzv, 3, ~.: , which hold the toner shell carrier material (20) between each other under pressure and transport it, -Λπβ main circulating device (35), the at least one of the rollers eir .: Heated temperature at which the toner image can be fixed to the carrier material, a torque transmission device (38, 41 to 43) connected to a shaft (31 ') at a first end of the first roller is and to this to the rotary drive of the same transmits the rotary force generated by a power source (40), and an auxiliary heating device (48, 49; 35 ¹ ^), which the first end of the first roller a greater amount of heat than that opposite to the first end 'feeds lying second end of the first roller to thereby keep the thermal expansion of the first and the second roller in such a state that a displacement of the toner image carrier material in the width direction from a predetermined transport path is prevented. 7. Apparatus according to claim 6, characterized in that the auxiliary heating device (48; 35 ') is continuously in operation during operation of the main heating device (35). 8. Apparatus according to claim 6, characterized in that the auxiliary heating device (48, 49) is operated intermittently during operation of the main heater (35). 9. Apparatus according to claim 6, characterized in that the main heating device (35) at the first end of the first roller (31) generates a greater amount of heat than on the side corresponding to the second end of the first roller and that the main heating device also serves as an auxiliary heating device (35 ' ₃ ). 909886/0844 - 4 - B 9816 10. Apparatus according to claim 6, characterized in that that the auxiliary heating device is a first auxiliary heating device (48) for heating the first end of the first roller (31) and a second auxiliary heating device (4 9) for heating the second end of the first roller, the second auxiliary heating device during the operation of the main heater (35) is operated intermittently. 11. Device for heating and fixing a Toner image on a carrier material, characterized by a first and a second roller (31 and 32, respectively) which are between hold each other under pressure the toner image carrier material (20) and transport it, a heating device (35), which heats at least one of the rollers to a temperature at which the toner image on the carrier material can be fixed, a detector device (50) for detecting the position of the toner image carrier material in the With regard to its width direction and a control device ™ device (46 to 49; Fig. 14) corresponding to one of the detector device generated signal the temperature difference between the opposing Ends of at least one of the rollers controls, thereby reducing the thermal expansion of the first and second rollers to maintain in such a thermal expansion state that a dislocation of the toner image carrier material in Width direction is prevented from a predetermined transport path out. 12. Device for heating and fixing a Toner image on a carrier material, characterized by a first and a second roller (31 and 32, respectively) which between each other under pressure of the toner image carrier material (20) Hold on and transport it, a 35 Heating device (35) covering at least one of the rollers 909886/0844 * JO "7 ■" Π -5- £ 9816 * - ^J ~ - ' ^u warmed to a temperature at which the Tonerbila ^ :. can be fixed to the carrier material, a Dreniiraf-c-ifeÄr-carrying device (38, 41 to 43} _f the ξ. :: a shaft (31 ') is connected to a first end of the first SaIr; e and to the first roller for those Rotary drive which is generated by a power source (40) r-rehkr?, :: "'transmits, a detector device {50}, the Eis Lacce of the toner image carrier material with respect to the Er = it-s:' - -direction detects, and a Cooling device: '47} - which, in accordance with a signal generated by the detector device, cools the second end of the first roller opposite the first end, thereby expanding the first and second rollers into one To hold thermal expansion state that a displacement of the toner image carrier material in the width direction thereof from a predetermined transport path is prevented. 13. Apparatus according to claim 2 or 12, characterized in that the cooling device (47) has a fan device. 14. The apparatus according to claim 13, characterized in that a device (37 ') for shielding the * ■ ·> second roller (32) is provided opposite the air flow generated by the blower device (47) and that the blower device sends a cooling air flow onto a shaft (31 ") at the second end of the first The roller (31) blows. 30th 15. Device for heating and fixing a toner image on a carrier material, characterized by a first and a second roller (31 and 32) which press the toner image carrier material between each other (20) hold and transport it, a main heating 909386/0844 'direction (35), the at least one of the rollers on a Heated temperature at which the toner image can be fixed to the carrier material, a rotational force transmission device (33, 41 to 43), which are attached to a shaft (31 ') a first end of the first roller is connected and the first roller for the rotary drive of a Power source (40) generated rotational force transmits, a detector device (50), the position of the toner image carrier material with regard to the width direction of the H) the same detected, and an auxiliary heating device (48, 49), the corresponding to a signal formed by the detector device to the first end of the first roller supplies greater amount of heat than the second end of the first roller opposite the first end to ■ 5 thereby the thermal expansion of the first and the second To keep the roller in such a state that there is a displacement of the toner image carrier material in the width direction the same from a predetermined transport path is prevented.
20th 16. The device according to claim 11, 12 or 15, characterized in that the detector device (44, 45) a device for detecting the temperature difference between the opposite ends of the first roller (31). 17. Device according to one of claims 11, 12 or 15, characterized in that the detector device (50) is a device that detects the location of the Edge of the toner image carrier material (20) with respect to the width direction of the same at at least one point detected with respect to the transport path of the toner image carrier material upstream or downstream of the gap between the first and second rollers (31 and 32, respectively). 909886/0844 18. Device according to one of claims 2, 6, 12 or 15, characterized in that the second roller (32) is optionally pressed against the first roller (315 or released from the same, the second roller at Pressure against the first roller by frictional force in Is rotated in accordance with the rotation of the first roller, and that the heating device (35) the first The roller is heated. 19. Device according to one of claims 1, 2, 6, 11, 12 or 15, characterized in that the toner image carrier material (20) is a long, uninterrupted one Paper web is. 909886/0844